Carbon dioxide (CO2) is the gaseous end product of the aerobic metabolism of oxygen. CO2 is highly soluble in body tissues, and readily diffuses from cells to blood, where circulation transports it to the lungs for elimination. Divers often ignore carbon dioxide, as CO2 is a normal part of life. However, CO2 may have definite and detrimental effects if a diver accumulates an excessive amount of...

The majority of industrial organic chemicals lack identifiable structural characteristics that result in specific biological activity. These nonpolar-nonelectrolytes are acutely toxic to aquatic organisms via a nonspecific mode of action termed narcosis. The toxicity of industrial chemicals eliciting nonpolar narcosis can be reliably predicted by log P (baseline toxicity models). Using single c...

Premedication must now be considered. It is desirable that the patient should be drowsy before the operation, but full basal narcosis is not always to be recommended, since it is important that the coughing reflex should have returned immediately after the operation, and, indeed, the patient should as a rule be able to cough voluntarily before leaving the table. If local analgesia only is conte...

The narcosis target lipid model (TLM) was developed to predict the toxicity of chemicals to aquatic organisms that act via narcosis. It is based on the hypothesis that target lipid is the site of toxic action within the organism, that octanol is the appropriate surrogate, and that target lipid has the same physical-chemical properties in all organisms. Here the TLM is extended to available fres...

The influence of nitrous oxide (N2O) narcosis on the response to exercise and inspiratory resistive loading was studied in thirteen male US Navy divers. Each diver performed an incremental bicycle exercise test at 1 ATA to volitional exhaustion while breathing a 23% N2O gas mixture and a nonnarcotic gas of the same PO2, density and viscosity. The same gas mixtures were used during four subseque...

Compressed air or a nitrogen-oxygen mixture produces from 0.3 MPa nitrogen narcosis. The traditional view was that anaesthesia or narcosis occurs when the volume of a hydrophobic site is caused to expand beyond a critical amount by the absorption of molecules of a narcotic gas. The observation of the pressure reversal effect on general anaesthesia has for a long time supported the lipid theory....

Before the beginning of the experiment all the rats were kept without food overnight. The isolation of the loop was performed under ether narcosis. The mesenterium of the first 10-15 cm. of jejunum in rats weighing 70-120 g. is so short that measurement of the length of the loop is rather uncertain. A 30 cm. loop was isolated in each rat, starting about 15 cm. below the pylorus, and the lumen w...